<!DOCTYPE html>
<html>
	<head>
		<meta charset="UTF-8">
		<title></title>
	<script type="text/javascript">
		
		var timer = setInterval(function(){
			alert('你好');
		},2000)
		
//		定时炸弹
		setTimeout(function(){
//			清理定时器
			clearInterval(timer);
		},5000)
	</script>
	</head>
	<body>
		
	</body>
</html>
